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Abstract:

A method and an apparatus for enciphering/deciphering digital rights
management object are provided. The DRM enciphering method includes the
following steps: A plurality of content objects which are divided from a
digital content are received. A plurality of DRM vectors are generated
according to tacit information between the DRM enciphering apparatus and
the DRM deciphering apparatus. The content objects are respectively
enciphered according to the DRM vectors to generate a plurality of DRM
objects.

Claims:

1. A digital rights management (DRM) enciphering method applicable to a
DRM enciphering apparatus and implemented by a processor, comprising:
Receiving a plurality of content objects which are divided from a digital
content; generating a plurality of DRM vectors according to a tacit
information between a DRM enciphering apparatus and a DRM deciphering
apparatus; and enciphering the plurality of content objects respectively
according to the plurality of DRM vectors to generate a plurality of DRM
objects.

2. The DRM enciphering method according to claim 1, wherein the
enciphering step comprises: enciphering the plurality of content objects
respectively according to the plurality of DRM vectors to generate a
plurality of vector enciphering objects; and enciphering the plurality of
vector enciphering objects according to a key information to generate the
plurality of DRM objects.

3. The DRM enciphering method according to claim 1, wherein the
enciphering step comprises: generating a plurality of enciphering vectors
according to a key information and the plurality of DRM vectors; and
enciphering the plurality of content objects according to the plurality
of enciphering vectors to generate the plurality of DRM objects.

4. The DRM enciphering method according to claim 1, wherein the tacit
information comprises a plurality of tacit values from which the
plurality of DRM vectors are obtained through a logical operation.

5. The DRM enciphering method according to claim 4, wherein the logical
operation is an exclusive-or (XOR) operation or a hash function
operation.

6. The DRM enciphering method according to claim 4, wherein the plurality
of tacit values comprises the information associated with the plurality
of content objects, the ID of the DRM deciphering apparatus, the
transaction number of the digital content, the request time of the DRM
deciphering apparatus, the previous last requested object ID of the DRM
deciphering apparatus, or the user information of the DRM deciphering
apparatus, or any combination of above.

7. The DRM enciphering method according to claim 1, wherein the plurality
of DRM vectors have a fixed length.

8. The DRM enciphering method according to claim 1, wherein the plurality
of DRM vectors are different values from each other.

9. A DRM object deciphering method, applicable to a DRM deciphering
apparatus having a transaction number of a digital content, and
implemented by a processor, comprising: generating a plurality of DRM
vectors according to a tacit information between a DRM enciphering
apparatus and a DRM deciphering apparatus; and deciphering the plurality
of DRM objects respectively according to the plurality of DRM vectors to
generate a plurality of content objects.

10. The DRM object deciphering method according to claim 9, wherein the
deciphering step comprises: deciphering the plurality of DRM objects
according to a key information to generate a plurality of vector
enciphering objects; and deciphering the plurality of vector enciphering
objects according to the plurality of DRM vectors to generate the
plurality of content objects.

11. The DRM object deciphering method according to claim 9, wherein the
content objects generation step comprises: generating a plurality of
enciphering vectors according to a key information and the plurality of
DRM vectors; and deciphering the plurality of DRM objects according to
the plurality of enciphering vectors to generate a plurality of content
objects.

12. The DRM object deciphering method according to claim 9, wherein the
tacit information comprises a plurality of tacit values from which the
plurality of DRM vectors are obtained through a logical operation.

13. The DRM object deciphering method according to claim 12, wherein the
logical operation is an exclusive-or (XOR) operation or a hash function
operation.

14. The DRM object deciphering method according to claim 12, wherein the
plurality of tacit values comprises the information associated with the
plurality of content objects, the ID of the DRM deciphering apparatus,
the transaction number of the digital content, the request time of the
DRM deciphering apparatus, the previous last requested object ID of the
DRM deciphering apparatus, or the user information of the DRM deciphering
apparatus, or any combination of above.

15. The DRM object deciphering method according to claim 9, wherein the
plurality of DRM vectors have a fixed length.

16. The DRM object deciphering method according to claim 9, wherein the
plurality of DRM vectors are different values from each other.

17. A DRM enciphering apparatus, comprising: a receiving unit for
receiving a plurality of content objects which are divided from a digital
content; a DRM vector generation unit for generating a plurality of DRM
vectors according to a tacit information between the DRM enciphering
apparatus and a DRM deciphering apparatus; and a DRM object generation
unit for enciphering the plurality of content objects respectively
according to the plurality of DRM vectors to generate a plurality of DRM
objects.

18. The DRM enciphering apparatus according to claim 17, wherein the DRM
object generation unit comprises: a vector enciphering unit for
enciphering the plurality of content objects respectively according to
the plurality of DRM vectors to generate a plurality of vector
enciphering objects; and a key enciphering unit for enciphering the
plurality of vector enciphering objects according to a key information to
generate the plurality of DRM objects.

19. The DRM enciphering apparatus according to claim 17, wherein the DRM
object generation unit comprises: an enciphering vector generation unit
for generating a plurality of enciphering vectors according to a key
information and the plurality of DRM vectors; and a vector enciphering
unit for enciphering the plurality of content objects according to the
enciphering vectors to generate the plurality of DRM objects.

20. The DRM enciphering apparatus according to claim 17, wherein the
tacit information comprises a plurality of tacit values from which the
plurality of DRM vectors are obtained through a logical operation.

21. The DRM enciphering apparatus according to claim 20, wherein the
logical operation is an exclusive-or (XOR) operation or a hash function
operation.

22. The DRM enciphering apparatus according to claim 20, wherein the
tacit values comprises the information associated with the plurality of
content objects, the ID of the DRM deciphering apparatus, the transaction
number of the digital content, the request time of the DRM deciphering
apparatus, the previous last requested object ID of the DRM deciphering
apparatus, or the user information of the DRM deciphering apparatus, or
any combination of above.

23. The DRM enciphering apparatus according to claim 17, wherein the
plurality of DRM vectors have a fixed length.

24. The DRM enciphering apparatus according to claim 17, wherein the
plurality of DRM vectors are different values from each other.

25. A DRM deciphering apparatus having a transaction number of a digital
content, comprising: a DRM vector generation unit for generating a
plurality of DRM vectors according to a tacit information between a DRM
enciphering apparatus and the DRM deciphering apparatus; and a content
object generation unit for deciphering the DRM objects respectively
according to the plurality of DRM vectors to generate a plurality of
content objects.

26. The DRM deciphering apparatus according to claim 25, wherein the
content object generation unit comprises: a key deciphering unit for
deciphering the plurality of DRM objects according to a key information
to generate a plurality of vector enciphering object; and a vector
deciphering unit for deciphering the plurality of vector enciphering
objects according to the plurality of DRM vectors to generate the
plurality of content objects.

27. The DRM deciphering apparatus according to claim 25, wherein the
content object generation unit comprises: an enciphering vector
generation unit for generating a plurality of enciphering vectors
according to a key information and the plurality of DRM vectors; and a
vector deciphering unit for deciphering the DRM objects according to the
enciphering vectors to generate a plurality of content objects.

28. The DRM deciphering apparatus according to claim 25, wherein the
tacit information comprises a plurality of tacit values from which the
plurality of DRM vectors are obtained through a logical operation.

29. The DRM deciphering apparatus according to claim 28, wherein the
logical operation is an exclusive-or (XOR) operation or a hash function
operation.

30. The DRM deciphering apparatus according to claim 28, wherein the
plurality of tacit values comprises the information associated with the
plurality of content objects, the ID of the DRM deciphering apparatus,
the transaction number of the digital content, the request time of the
DRM deciphering apparatus, the previous last requested object ID of the
DRM deciphering apparatus, the user information of the DRM deciphering
apparatus, or any combination of above.

31. The DRM deciphering apparatus according to claim 25, wherein the
plurality of DRM vectors have a fixed length.

32. The DRM deciphering apparatus according to claim 25, wherein the
plurality of DRM vectors are different values from each other.

Description:

[0001] This application claims the benefit of Taiwan application Serial
No. 100144911, filed Dec. 6, 2011, the disclosure of which is
incorporated by reference herein in its entirety.

BACKGROUND

[0002] 1. Technical Field

[0003] The disclosed embodiments relate in general to a method and an
apparatus for enciphering/deciphering digital rights management object.

[0004] 2. Description of the Related Art

[0005] Along with the popularization and diversification of the service of
the digital content, the digital rights management is being generally
applied to each electronic product or Internet service. The purposes of
the digital rights management are for protecting the spread of the
digital content from infringement such as unauthorized copy or use of the
digital content and for defining the commercial operation mode according
to the form of the digital content and the function of the related
electronic products. Currently, most of the digital rights systems are
combined with the online paying system to form a complete digital online
service.

[0006] The Open Mobile Alliance (OMA) integrates plenty of service
standard organizations (such as WAP forum, Wireless Village, SyncML, LiF,
and so on) of the field, and aims to develop joint open standards for
being conformed to the market demand and for helping to establish the
compatible and interactive services working across nations, operators,
and mobile terminals. Currently, the OMA has already been developed into
a global standard organization having more than 350 members. The OMA has
established 15 work teams, such as Requirements, Architecture, Security,
Interoperability, Browser & Content, Location, and Push to talk over
cellular, for developing different standards for the application layer
with respect to different value-added services.

[0007] Different DRM systems are working online, and meantime the OMA
defines a standard of DRM. The latest version is OMA DRM 2.1. Each of the
standards of OMA and the different DRM systems defines the related rights
of the digital content purchased by a user, and encrypts the delivered
digital content. Only the authorized users and apparatuses are allowed to
use the delivered digital content.

[0008] However, a user could have many apparatuses, for example, the home
computer, the notebook computer, the handheld device, used in different
conditions. Therefore, each DRM system defines a domain or a mechanism
similar to a domain. A user may define his/her own devices as being in
the same domain, such that the user is allowed to download or copy or use
the content in many devices after buying the digital content one time.
Certainly, an apparatus can only belong to one domain, and the quantity
of the apparatuses in the one domain is limitary. The corresponding
relationship of the domain makes the spread of the digital content much
easier. Unlike the purchase of general software which provides
authorization with respect to a machine (apparatus), the purchase of the
digital content provides authorization with respect to a user and his/her
machine (apparatus) of the domain because the purchase of the digital
content is for the use (or browsing) of the user.

SUMMARY

[0009] The disclosure is directed to a method and an apparatus for
enciphering/deciphering digital rights management object.

[0010] According to one embodiment, a DRM enciphering method is provided.
The DRM enciphering method is applicable to DRM enciphering apparatus and
may be implemented by a processor. The DRM enciphering method includes
the following steps. A plurality of content objects which are divided
from a digital content are received. A plurality of DRM vectors are
generated according to tacit information between the DRM enciphering
apparatus and the DRM deciphering apparatus. The content objects are
respectively enciphered according to the DRM vectors to generate a
plurality of DRM objects.

[0011] According to another embodiment, a DRM object deciphering method is
provided. The DRM object deciphering method is applicable to a DRM
deciphering apparatus having a transaction number of a digital content
and may be implemented by a processor. The DRM object deciphering method
includes the following steps. A plurality of DRM vectors are generated
according to tacit information between the DRM enciphering apparatus and
the DRM deciphering apparatus. A plurality of DRM objects are
respectively deciphered according to the DRM vectors to generate the
content objects.

[0012] According to an alternative embodiment, a DRM enciphering apparatus
is provided. The DRM enciphering apparatus includes a receiving unit, a
DRM vector generation unit and a DRM object generation unit. The
receiving unit receives a plurality of content objects which are divided
from a digital content. The DRM vector generation unit generates a
plurality of DRM vectors according to tacit information between the DRM
enciphering apparatus and the DRM deciphering apparatus. The DRM object
generation unit respectively enciphers the content objects according to
the DRM vectors to generate a plurality of DRM objects.

[0013] According to an alternative embodiment, a DRM deciphering apparatus
is provided. The DRM deciphering apparatus having a transaction number of
a digital content includes a DRM vector generation unit and a content
object generation unit. The DRM vector generation unit generates a
plurality of DRM vectors according to tacit information between the DRM
enciphering apparatus and the DRM deciphering apparatus. The content
object generation unit respectively deciphers the DRM objects according
to the DRM vectors to generate the content objects.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1 is a schematic diagram showing a DRM enciphering apparatus
and a DRM deciphering apparatus;

[0026] In the following detailed description, for purposes of explanation,
numerous specific details are set forth in order to provide a thorough
understanding of the disclosed embodiments. It will be apparent, however,
that one or more embodiments may be practiced without these specific
details. In other instances, well-known structures and devices are
schematically shown in order to simplify the drawing.

DETAILED DESCRIPTION

[0027] Referring to FIG. 1, FIG. 2 and FIG. 3. FIG. 1 is a schematic
diagram showing a DRM enciphering apparatus and a DRM deciphering
apparatus. FIG. 2 is a flowchart of a DRM enciphering method. FIG. 3 is a
flowchart of a DRM object deciphering method. The DRM enciphering
apparatus 11 includes a receiving unit 111, a DRM vector generation unit
112 and a DRM object generation unit 113. The DRM deciphering apparatus
12 having a transaction number of a digital content includes a DRM vector
generation unit 121 and a content object generation unit 122. The DRM
enciphering apparatus 11 may be realized by a server, a client or a
processor. The DRM deciphering apparatus 12 may be realized by a server,
a client or a processor. When the DRM enciphering apparatus 11 is a
server, the DRM deciphering apparatus 12 is a client. Conversely, when
the DRM enciphering apparatus 11 is a client, the DRM deciphering
apparatus 12 is a server. The client is such as a home computer, a tablet
PC, a notebook computer, or a handheld device. The DRM enciphering method
is applicable to the DRM enciphering apparatus 11, and includes the
following steps:

[0028] As shown in step 21, the receiving unit 111 receives a plurality of
content objects S2 which are divided from a digital content S1. The
digital content is such as a book, a magazine, a cartoon, a song or a
film. The receiving unit 111 receives a plurality of content objects S2
which are divided from the digital content S1 according to the context or
paragraphs recognizable to the user. Alternatively, the receiving unit
111 receives a plurality of content objects S2 which are divided from the
digital content S1 according to file size (or stationery points of
voice).

[0029] As shown in step 22, the DRM vector generation unit 112 generates a
plurality of DRM vectors S3 according to tacit information S4 between the
DRM enciphering apparatus 11 and the DRM deciphering apparatus 12. The
DRM vectors S3 have a fixed length, and are different values from each
other. As shown in step 23, the DRM object generation unit 113 enciphers
the content objects S2 respectively according to the DRM vectors S3 to
generate a plurality of DRM objects S5.

[0030] The DRM object deciphering method is applicable to DRM deciphering
apparatus 12, and comprising the followings. As shown in step 31, the DRM
vector generation unit 121 generates a plurality of DRM vectors S3
according to tacit information S4 between the DRM enciphering apparatus
11 and the DRM deciphering apparatus 12. As shown in step 32, the content
object generation unit 122 deciphers the DRM objects S5 respectively
according to the DRM vectors S3 to generate a plurality of content
objects S2.

[0031] It is noted that the tacit information S4 is already obtained by
the DRM enciphering apparatus 11 and the DRM deciphering apparatus 12
before the delivery of the DRM object S5. Theoretically, the tacit
information does not need to be transmitted during the delivery of the
DRM object S5. The tacit information may further include a plurality of
tacit values from which the DRM vectors S3 are obtained through a logical
operation. The logical operation may have plenty of implementations. For
example, the logical operation is an exclusive-or (XOR) operation or a
hash function operation. The tacit information, not transmitted during
the delivery of the DRM object S5, is further protected from being
deciphered by illegal users.

[0032] The aforementioned tacit values include, for example, the
information related to the content object S2, the ID of the DRM
deciphering apparatus 12, the transaction number of the digital content
S1, the request time of the DRM deciphering apparatus 12, the previous
last requested object ID of the DRM deciphering apparatus 12 or the user
information of the DRM deciphering apparatus 12 or any combination of
above.

[0033] The information related to the content object S2 is such as a
serial number of the content object. The ID of the DRM deciphering
apparatus 12 is such as a machine number of the DRM deciphering apparatus
12. The transaction number of the digital content S1 is such as
transaction information when the user purchases the digital content. The
request time of the DRM deciphering apparatus 12 is such as the previous
time when the DRM deciphering apparatus 12 requests a DRM object of the
RM enciphering apparatus 11. The previous last requested object ID of the
DRM deciphering apparatus 12 is such as the serial number of the DRM
object requested of the DRM enciphering apparatus 11 by the DRM
deciphering apparatus 12. If the

[0034] DRM deciphering apparatus 12 has never requested any DRM objects of
the DRM enciphering apparatus 11, the default value of the previous last
requested object ID is set as 0. The user information is such as an
account number or a password.

[0035] Referring to FIG. 4, a schematic diagram showing the generation of
a DRM vector is shown. For example, the aforementioned tacit value
includes the previous last requested object ID S41 of the DRM deciphering
apparatus 12, the user information S42 of the DRM deciphering apparatus
12, the ID S43 of the DRM deciphering apparatus 12 and the request time
S44 of the DRM deciphering apparatus 12. The DRM vector generation unit
performs a hash function operation on the previous last requested object
ID S41, the user information S42, the ID S43 and request time S44
respectively to generate a previous last requested object ID S41', a user
information S42', an ID S43' and a request time S44' respectively. Then,
the DRM vector generation unit performs an exclusive-or (XOR) operation
on the previous last requested object ID S41', the user information S42',
the ID S43' and the request time S44' to generate a plurality of DRM
vectors S3.

[0036] Referring to FIG. 5, FIG. 6, FIG. 7 and FIG. 8. FIG. 5 is a first
schematic diagram showing a DRM object generation unit. FIG. 6 is a first
detailed flowchart of step 23. FIG. 7 is a first schematic diagram
showing a content object generation unit. FIG. 8 is a first detailed
flowchart of step 32. In one embodiment, the aforementioned DRM object
generation unit comprises, for example, a vector enciphering unit 1121
and a key enciphering unit 1122. In one embodiment, the aforementioned
step 23, for example, further includes steps 231˜232. As shown in
step 231, the vector enciphering unit 1121 enciphers the content objects
S2 respectively according to the DRM vectors S3 to generate a plurality
of vector enciphering objects S6. As shown in step 232, the key
enciphering unit 1122 enciphers the vector enciphering objects S6
according to the key information S7 to generate a plurality of DRM
objects S5.

[0037] In one embodiment, the aforementioned content object generation
unit comprises, for example, a key deciphering unit 1221 and a vector
deciphering unit 1222. In one embodiment, the aforementioned step 32, for
example, further includes steps 321˜322. As shown in step 321, the
key deciphering unit 1221 deciphers the DRM objects S5 according to the
key information S7 to generate a plurality of vector enciphering objects
S6. As shown in step 322, the vector deciphering unit 1222 deciphers the
vector enciphering objects according to the DRM vectors S7 to generate a
plurality of content objects S2.

[0038] Referring to FIG. 9, FIG. 10, FIG. 11 and FIG. 12. FIG. 9 is a
second schematic diagram showing a DRM object generation unit. FIG. 10 is
a second detailed flowchart of step 23. FIG. 11 is a second schematic
diagram showing a content object generation unit. FIG. 12 is a second
detailed flowchart of step 32. In one alternate embodiment, the
aforementioned DRM object generation unit includes, for example, an
enciphering vector generation unit 1123 and a vector enciphering unit
1124. In one alternate embodiment, the aforementioned step 23, for
example, further includes steps 233˜234. As shown in step 233, the
enciphering vector generation unit 1123 generates a plurality of
enciphering vectors S8 according to the key information S7 and the DRM
vectors S3. As shown in step 234, the vector enciphering unit 1124
enciphers the content object S2 according to the enciphering vectors S8
to generate a plurality of DRM objects S5.

[0039] In one alternate embodiment, the aforementioned content object
generation unit includes, for example, an enciphering vector generation
unit 1223 and a vector deciphering unit 1224. In one alternate
embodiment, the aforementioned step 32, for example, further includes
steps 323˜324. As shown in step 323, the enciphering vector
generation unit 1223 generates a plurality of enciphering vectors S8
according to the key information S7 and the DRM vectors S3. As shown in
step 324, the vector deciphering unit 1224 deciphers the DRM objects S5
according to the enciphering vectors S8 to generate a plurality of
content objects S2.

[0040] The method and apparatus for enciphering/deciphering DRM object are
capable of dividing a digital content into different content objects
according to actual context, pattern or browsing mode of the digital
content, and further enciphering the content object according to the DRM
vectors. When the user only purchases the digital rights for one copy of
digital content, theoretically, the user only owns one use right instead
of many use rights with respect to the digital content. Therefore, when
there are many users, the corresponding use rights should be many as
well. That is, at any time, different users are not allowed to own the
same use right. To resolve such problem, the method and the apparatus for
enciphering/deciphering DRM object of the disclosure not only control the
correlation of the content objects browsed by the user with an apparatus
but also prohibit the transferability of the same digital content between
different apparatuses. Within a short period of time, the DRM apparatus
system allows the same DRM object to be browsed by only one apparatus.

[0041] It will be apparent to those skilled in the art that various
modifications and variations can be made to the disclosed embodiments. It
is intended that the specification and examples be considered as
exemplary only, with a true scope of the disclosure being indicated by
the following claims and their equivalents.